FIG. 1 is a diagram which summarizes the architecture of a telecommunications network enabling a telecommunications terminal TE1 to communicate with a terminal TE2.
An equipment TE1 is connected to a switch SW1 of an operator 01. The switch SW1 is connected to a switch SW2 of the same operator, for example, which is connected to a switch SW3 of an operator O2. A terminal TE2 is connected to the switch SW3.
Accordingly, calls between the terminals TE1 and TE2 are processed by telecommunications equipments for which the signaling standards are not necessarily the same.
Switching centers (also referred to as switches) such as the equipments SW1, SW2, SW3 are therefore provided in the network. In practice there is no reason for them to be from the same supplier or operator. Thus the network can route data streams, voice streams and control streams.
The control stream is concerned with call protocols. For call protocols there are several standards, including the B-ISUP standard of the International Telecommunication Union (ITU), the PNNI standard of the ATM (Asynchronous Transmission Mode) Forum and the SS7 standard of the European Telecommunications Standards Institute (ETSI).
The architecture of a switching center (also referred to as a switch) comprises various S1 modules, including:                a signaling processing module        a call control module CA, S1, S2, S3 and        a resource management module CR allocating channels via physical links.        
In practice, the signaling module of a switch implements the call protocol which enables it to communicate with another switch.
The call control module CA is the core of the system. It is an automaton which creates a process for each type of call received.
In practice, the call control module creates a process to handle the call when a line goes to the off-hook condition for a telephone call.
To this end, a generic process (also referred to as a program) is provided in the module and is adapted to create another process to handle the call.
As there are several signaling standards, the same equipment can include different signaling modules conforming to different signaling standards.
The above architecture is shown diagrammatically in FIG. 2. Signaling modules S1, S2, S3 conforming to the three standards that exist at present are installed in a switch SW2 and connected to the core, i.e. to the call handling module CA.
This problem is relatively new, but is becoming more difficult to solve because new operators can come into play and because it may be desirable to modify existing standards.
Accordingly, each time that a new standard appears, the equipment must evolve to take account of it.